A Pentagon briefing on Saturday said the strikes had “set the Syrian chemical weapons programme back for years”.

Later there was a bitter exchange between the US and Russia at the United Nations.

The wave of strikes is the most significant attack against President Bashar al-Assad’s government by Western powers in seven years of Syria’s civil war.

Responding to the strikes, Mr Assad said in comments published by his office: “This aggression will only make Syria and its people more determined to keep fighting and crushing terrorism in every inch of the country.”

Where was hit?

At a Pentagon briefing on Saturday, Lt Gen Kenneth McKenzie listed the three targets that had been struck in a “precise, overwhelming and effective” manner:

The Barzah chemical weapons research and development centre near Damascus was hit by 76 missiles, 57 of them Tomahawk cruise missiles, and “destroyed”

The Him Shinshar chemical weapons storage facility near Homs was hit by 22 missiles – nine US Tomahawks, eight British Storm Shadows and five naval cruise missiles and two Scalp cruise missiles launched by France

The Him Shinshar chemical weapons bunker facility near Homs was targeted with seven Scalp missiles and was “successfully hit”

Gen McKenzie said the “initial indications are that we accomplished the military objectives without interference from Syria”.

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Media captionGen Kenneth McKenzie: “We deployed 105 weapons”

He said “none of the aircraft or missiles were successfully engaged” by defence systems and all aircraft had returned.

Gen McKenzie said about 40 Syrian defence missiles were fired, mostly after the targets were hit. No Russian defence systems were operated, he said.

Media captionAmateur footage shows strikes on a military research facility in Damascus, while state TV shows the damage

What was said at the UN?

At an emergency meeting of the UN Security Council called by Russia, the Russian envoy to the UN, Vassily Nebenzia, read out a quote from President Putin saying the action of the US and its allies had made a “catastrophic situation in Syria even worse”.

Mr Putin accused the allies of “cynical disdain” in acting without waiting for the results of a chemical watchdog investigation into the Douma attack. The Organisation for the Prohibition of Chemical Weapons (OPCW) inspectors are expected to arrive in the area this weekend.

US envoy Nikki Haley said the strikes were “justified, legitimate and proportionate”.

She said the US and its allies had given diplomacy “chance after chance” but Russia had continued to veto UN resolutions.

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Media captionDonald Trump and Theresa May on the air strikes in Syria

She said: “We cannot stand by and let Russia trash every international norm and allow use of chemical weapons to go unanswered.”

Ms Haley said she had spoken to President Trump and he had said the US was “locked and loaded” if Syria used chemical weapons again.

She said: “If the US draws a red line, it enforces a red line.”

Bashar Jaafari, Syria’s envoy to the UN, repeated that the alleged Douma attack was a “masquerade” mounted by rebels.

He also said OPCW inspectors had previously visited the targeted Barzeh site and reported no chemical weapons activities there.

UN Secretary General Antonio Guterres said he wanted to remind all members that “there is an obligation to act consistently with the charter of the UN and international law in general” and added that there was “no military solution” to the Syria crisis.

The UN Security Council rejected a Russian resolution condemning the strikes.

What role did the UK and France play?

According to the UK Ministry of Defence, four RAF Tornado jets hit a site near Homs with eight Storm Shadow cruise missiles.

Prime Minister Theresa May said there was “no practicable alternative to the use of force” but also added that the strikes were not about “regime change”.

French President Emmanuel Macron also confirmed his country’s participation in the operation.